Re: How to choose new master from slaves.?

On 8/6/22 15:45, Peter J. Holzer wrote:
> On 2022-08-06 15:06:06 -0500, Ron wrote:
>> On 8/6/22 03:40, Peter J. Holzer wrote:
>>> Using sync replication on an unstable link is probably not a good idea.
>>> Every time the link goes down, A freezes. Is this what you want?
>> I had to fight my end users about how to replicate a SQL Server database
>> across a WAN.  They of course wanted it synchronously replicated, but I
>> insisted that was a horrible idea, for the exact reason you mentioned
>> (though it "only" freezes when the untransmitted transmitted transaction
>> logs fill of the primary database's disk).
> Doesn't synchronous mean that a commit only returns when the transaction
> has been replicated?

Correct.  I don't know what I was thinking when I wrote that.

Probably that transaction log data gets queued up and not deleted if it
can't send the data across.

> (The database can work on other transactions in the meantime, but that
> client is blocked.)

Eventually any client doing writes blocks.  Readers might block if a writer
took an exclusive lock,

--
Angular momentum makes the world go 'round.